Sliding door construction for corrugated containers and the like



April 20, 1965 R. HRHODGSON ETAL 3,179,314

SLIDING DOOR CONSTRUCTION FOR CORRUGATED CONTAINERS AND THE LIKE FiledJan. 5, 1964 2 Sheets-Sheet l INVENTOR REGINALD H. Hoossou AND Y FRANKW.THoMAs,

ATTO Fl N EYS April 1965 R. H. HODGSON ETAL 3,179,314

SLIDING DOOR CONSTRUCTION FOR CORRUGATED CONTAINERS AND THE LIKE FiledJan. 3, 1964 2 Sheets-Sheet 2 INVENTOR. REGINALD H. Hooasou AND 28 BYFRANK W. THOMAS,

yw llwhw ATTORNEYS United States Patent 3,179,314 SLIDING DOORCONSTRUCTION FOR CORRU- GATED CONTAINERS AND THE LIKE Reginald H.Hodgson, Atlanta, Ga, and Frank W.

Thomas, Baltimore, Md., assignors to Albemarle Paper ManufacturingCompany, Richmond, Va., a corporation of Virginia Filed Jan. 3, 1964,Ser. No. 335,611 7 Claims. (Cl. 222--561) This invention has to do withlarge size containers, and relates more particularly to the provision ofa sliding door opening by means of which the contents/of the containermay be readily dispensed.

While its utility is not so limited, the instant invention isparticularly suited for use with large size corrugated paperboardcontainers in which as much as one thousand pounds or more of fertilizeror similar materials are packaged. Such large size packages areobviously extremely diificult to handle, and once the package has beenplaced on a farm truck or other vehicle, it is highly desirable for theuser to be able to dispense the material directly from such vehiclewithout having to 'tear apart the container or repeatedly move it aboutor otherwise adjust its position.

Accordingly, a principal object of the instant invention is theprovision of a sliding 'door assembly which may be readily associatedwith a large size container by the simple expedient of fitting suchassembly in an opening in the container, the construction of theassembly being such that it will be held in place in the container bythe weight of the contents which will serve to urge flange portions ofthe assembly into sealing engagement with the container Walls in theareas immediately surrounding the opening therein.

A further object of the instant invention is the provision of a doorassembly of the character described which is provided with a slidingdoor panel which may be readily and easily opened to permit thecontrolled discharge of the contents of a container with which the doorassembly is associated.

Still a further object of the instant invention is the provision of adoor assembly of the character described which is extremely sturdy andcapable of withstanding considerable abuse, and yet is of relativelysimple and inexpensive construction.

The foregoing, together with other objects of the invention which willappear hereinafter or which will be apparent to the skilled worker inthe art upon reading this specification, we accomplish by thoseconstructions and arrangements of parts of which we shall now describecertain exemplary embodiments.

Reference is now made to the accompanying drawings wherein:

FIGURE 1 is a fragmentary front elevational view illustrating the bottomportion of a conventional heavy duty corrugated container incorporatinga door assembly in accordance with the instant invention.

FIGURE 2 is an enlarged fragmentary sectional view taken along. the line2-2 of FIGURE 1.

FIGURE 3 is an enlarged perspective view of a door assembly inaccordance with the instant invention.

. FIGURE 4 is an enlarged perspective view of a modified door assemblyin accordance with the instant inventlon.

FIGURE 5 is a rear elevational view of the modification of the inventionillustrated in FIGURE 4.

structure having sufficient strength to adequately package.

the material being handled, whether it be fertilizer or other comparablesubstances. Preferably the container will be of the type having atubular body with closure flaps at the top and bottom ends thereof. Sucha container is indicated generally at i in FIGURE 1 of the drawings, andthe container will be provided with a rectangular openings 2 the bottomedge of which is essentially co-planar with the bottom wall 3 of thecontainer. Fitted snugly within the opening is a door assembly,indicated generally at 4, which comprises a sliding door part 5 and aframe part 6.

The door part 5 is of rectangular configuration and is preferably formedfrom an essentially rigid material such as plywood, pressed board, orthe like. Preferably it will be provided with ahandle or knob 7 by meansof which the door part may be readily opened and closed.

The frame part, on the other hand, is preferably fabricated from sheetmetal, such as conventional steel strip, which is cut, formed and Weldedto provide a pair of opposing channels 8 and 9 which define the oppositesides of the frame. Side flanges 10 and 11 project outwardly from thechannels 8 and 9, respectively, at their rearward edges; and similarly atop flange 12 projects upwardly from the upper edges of the channels. Aswill be evident, the flanges it 11, and 12 are essentially co-planarand, when the .door assembly is fitted into the opening 2,

the flanges are juxtaposed to the inner surfaces of the container wallin which the opening is formed, with the channels 8 and 9 projectingoutwardly through the opening. In similar fashion, the frame part isprovided with a'bottom flange 13 which projects rearwardly from thebottom edges of the channels 3 and 9 and hence lies in a plane atessentially right angles to the channels 3 and 9 and the flanges Ill, 11and 12. The flange 13 thus overlies the bottom wall 3 of the containerand coacts with the other flanges to retain the frame part in position.

As should now be evident, the door part 5 is adapted to slide verticallyin the channels 8 and 9; and in this connection, it has been founddesirable to line the channels 8 and 9 internally with guide tracks 14and 15 which are generally U-shapcd in cross section and of a size tojust nicely receive the opposite side edges of the door part for slidingmovement therein. The guide tracks may be formed from wood, plastic, orother material which will readily permit sliding movement of the doorpart. Such guide tracks have been found to be particularly desirablewhere the metallic frame part is coated with a plastic or resinousmaterial by a dipping operation, such resinous or plastic coatingserving as a protective covering for the metallic parts and acting toprevent corrosive attack by the contents of the container. Suchexpedient is highly desirable where fertilizers are being packaged sincesuch materials can be highly corrosive to metallic surfaces.

For example, after the metallic frame parts are fabricated, they arecleaned, primed, preheated, and then coated by being dipped in a bath ofa plastic substance, such as Plastisol, which is a polyvinyl chlorideresin dis ersed in a liquid plasticiser along with colorants,stabilizers and other modifying agents, whereupon the coating is curedby heat. This treatment results in a continuous all-over protectivecoatin enveloping the entire frame.

It will also be evident, particularly from FIGURE 2 of the drawings,that the dimensioning of the frame parts are such that when the frame isproperly positioned in the opening in the container, the channels 8 and9 will project through the opening with the innermost surface of thedoor part positioned to just clear the outermost surface of thecontainer side wall. The door opening may be thus readily opened bysliding the door part 5 upwardly so that it assumes the positionillustrated in dotted lines in FlGURE 2, in which position the contentsof the carton will readily flow outwardly through the uncovered opening.Obviously, the door part may be subsequently moved downwardly to closethe opening and arrest the flow of contents.

' Referring now to FIGURES 4 and 5 of the drawings, we have thereinillustrated a modification of the invention wherein the opposing sidemembers 16 and 17 of the frame part are not truly channel shaped, butrather have guide track engaging flanges 18 and 19 on their outermostsides against which the guide tracks 20 and 21 are seated. In thisinstance, however, the guide tracks are held in place by means of pairsof ears 21, 22, and 23, 24. The ears 21 and 22 are formed as an integralextension of a rearwardly directed flange 25 which is connected alongdisposed flange 27. Actually, the entire frame struc:

ture is formed from a single strip of metal, with the .ex-

ception of the strip 28 which is welded or otherwise secured to thebottom flange 13 and mounts the ears 23, 24 at its opposite ends, andthe corner pieces 29 and -30 which extend between the side flanges 10and 11 and the top flange 12. If desired, the strip 28 may be providedwith an elevated sill portion 31 adapted to abut against the lowermostinside surface of the door part 5 when it is in the closed position.Such sill tends to prevent leakage of the contents from beneath the dooropening. As before, it is preferred that the entire frame be coated witha covering of protective plastic or the like.

As should now be evident, the door assemblies of the instant inventionprovide a sturdy, yet easily installed means for dispensing controlledquantities of material from a large size container utilizing containerswhich are of conventional construction.

Having thus described our invention in certain exemplary embodiments,and with the understanding that modifications may be made thereinwithout departing from its spirit and purpose, what we desire to secureand protect by Letters Patent is:

1. In a container having enclosing body walls, an open ing formed in oneof said body walls adjacent the bottom wall of said container, a doorstructure in said opening comprising a frame part having outwardlyprojecting top and side flanges positioned to make face-to-face contactwith the inner surfaces of the body wall in which said opening isformed, a flange projecting inwardly from the bottom of said frame inface-to-face contact with the inner surface of said container bottomwall, said frame part having a pair of oppositely directed verticallydisposed channel members projecting forwardly through said opening atthe opposite sides thereof and acting to define door receiving guideslying immediately beyond the outer surface of the said body wall inwhich said opening is formed, and a'door panel slidably received in saidchannel members for opening and closing the opening in said container.

2. In a container having enclosing body walls, an opening formed in oneof said body walls adjacent the bottom wall of said container, a doorassembly in said opening comprising a frame part having outwardlyprojecting top and side flanges positioned to make face-to-face contactwith the inner surfaces of the said body wall in which said opening isformed, a flange projecting inwardly from the bottom of said frame partin face-to-face contact with the inner surface of said container bottomwall, said frame part having a pair of oppositely directed verticallydisposed channel members projecting forwardly through said opening atthe opposite sides thereof, guide tracks mounted in said channel membersfor slidably receiving a door panel, said guide tracks being positionedso as to receive a door panel with the inner surface of said door panelpositioned to just clear the outer surface of the said container wall inwhich the opening is formed, and a door panel slidably received in saidguide tracks.

3. The structure claimed in claim 2 wherein said channel members areU-shaped in cross section, and wherein said guide tracks are of a sizeto be snugly received within said U-shaped channels.

4. The structure claimed in claim 2 wherein said channel members eachhave a flange along one side edge, and wherein said guide tracks aresecured in said channels bymeans of bendable ears positioned adjacentthe upper and lower extremities of said guide tracks at the sidesthereof opposite said flanges.

5. The structure claimed in claim 2 wherein said frame part, exclusiveof said guide tracks, is covered in its entirety with a plasticmaterial, whereby to render said flange structure impervious tocorrosive attack by the contents of the container.

6. A door assembly for use in conjunction with a dispensing openinghaving its bottom edge lying along the bottom wall of a container, saiddoor assembly comprising a frame part and a door part, said frame parthaving outwardly projecting top and side flanges and a rearwardlyprojecting bottom flange, vertically disposed frameforrning membersprojecting forwardly from the inner side edges of said side flanges,guide track means mounted on said frame members and positioned toslidably receive a door forming panel, and a door forming panel slidablyreceived between said guide tracks.

v 7. The structure claimed in claim 6 wherein said frame part at leastis formed from metal completely covered with a non-metallic protectivecovering of imperforate character.

References Qited in the file of this patent UNITED STATES PATENTS1,630,538 Micallef May 31, 1927 2,248,766 Landesman July 8, 1941FRANKLIN T. GARRETT, Primary Examiner.

1. IN A CONTAINER HAVING ENCLOSING BODY WALLS, AN OPENING FORMED IN ONEOF SAID BODY WALLS ADJACENT THE BOTTOM WALL OF SAID CONTAINER, A DOORSTRUCTURE IN SAID OPENING COMPRISING A FRAME PART HAVING OUTWARDLYPROJECTING TOP AND SIDE FLANGES POSITIONED TO MAKE FACE-TO-FACE CONTACTWITH THE INNER SURFACES OF THE BODY WALL IN WHICH SAID OPENING ISFORMED, A FLANGE PROJECTING INWARDLY FROM THE BOTTOM OF SAID FRAME INFACE-TO-FACE CONTACT WITH THE INNER FURFACE OF SAID CONTAINER BOTTOMWALL, SAID FRAME PART HAVING A PAIR OF OPPOSITELY DIRECTED VERTICALLYDISPOSED CHANNEL MEMBERS PROJECTING FORWARDLY THROUGH SAID OPENING ATTHE OPPOSITE SIDES THEREOF AND ACTING TO DEFINE DOOR RECEIVING GUIDESLYING IMMEDIATELY BEYOND THE OUTER SURFACE OF THE SAID BODY WALL INWHICH SAID OPENING IS FORMED, AND A DOOR PANEL SLIDABLY RECEIVED IN SAIDCHANNEL MEMBERS FOR OPENING AND CLOSING THE OPENING IN SAID CONTAINER.